Abstract: Objective To construct eukaryotic expression vector of hepatitis C virus (HCV) core protein, and investigate the effect of HCV Core protein on the autophagy of human cervical cancer HeLa cells. Methods The fragment of core was obtained by PCR from HCV replicon plasmid pJFH1. After purification and recovery, the DNA fragment was connected with the PLVX-IRES-ZsGreen1 vector using the homologous recombination method. DNA sequencing was used to verify the correctness of the sequence. PLVX-IRES-ZsGreen1-core was transfected into HeLa cells. Cells were divided into PLVX-IRES-ZsGreen1-core recombinant plasmid transfection group, PLVX-IRES-ZsGreen1 empty carrier transfection control group and control group without transfection plasmid blank. Western blot assay and immunofluorescence(IF) were applied to detect the expression of HCV Core protein and the autophagy-related biomarker (microtubuleassociated protein 1 light chain3, LC3) in HeLa cells. Results PLVX-IRES-ZsGreen1-core recombinant plasmid wasobtained. The sequencing results showed that the sequence of recombinant plasmid was completely corrected, and the HCV Core protein can be effectively expressed in HeLa cells. The results of Western blot assay and immunofluorescence also showed that LC3 Ⅱ protein level and LC3 foci were increased significantly in cells with HCV Core protein. The level of LC3 II was significantly higher in PLVX-IRES-ZsGreen1-Core recombinant plasmid transfection group (1.069±0.049) than that in PLVX-IRES-ZsGreen1 empty vector transfection control group (0.776 ± 0.047, P<0.05). Conclusion The eukaryotic expression vector of HCV Core is successfully constructed, and the HCV Core protein can induce autophagy in HeLa cells.

Key words: hepatitis C, hepacivirus, viral core proteins, autophagy, recombinant plasmid